Bluestuff NDX Formula Racing Rear Brake Pads (DP5680NDX) by EBC®. Bluestuff NDX is an intermediate grade trackday and race pad making it the material of choice for many club level racers and serious trackday enthusiasts. However, due to Bluestuff having excellent cold friction and being very controllable, this compound has quickly become the brake pad of choice for performance road car drivers in USA and Asia markets where R90 homologation does not apply.